Self-centering tool-holder



w. w. BAKER AND F. w. FRANKLIN. SELF CENTERING TOOL HOLDER.

, APPLICATION FILED MAY 16. 1919. 1,376,791 Patented May 3, 1921.

W BY? ATTORNEYS- UNITED STATES A PATENT OFFlC-E.

WALTER W. BAKER AND FREDERICK W. FRANKLIN, OF SYRACUSE, NEW YORK.

SELF-CENTERING TOQL-HOLDER.

Specification of Letters Patent.

Patented May 3', 1921.

Application filed Kay 16, 1919. Serial No. 297,603.

construction and highlyeificient and durable in use.

In describing this invention reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is an elevation of this tool holder.

Fig. 2 is an elevation, looking to the right or left in Fig. 1, the upper portion. being shown partly in section.

F'gs. 3 and 4 are opposing face views of the body and the tool holding member.

Fig. 5 is a face view of the collar associated with the tool holding member.

This self-centering tool holder comprises a body, and a tool holding member arranged end .to end, the body and said member being formed with interlocking means which transmits the rotation of the bodyto said member but which permits the body and said memberto have relative centering radial movement, and means for coupling the body and said member together, the

coupling means being operable to rigidly unite the body and the tool holding member after said memberhas centereditself.

of a shank having a head 2 at one end.

3 is the tool holding member whichhas a threaded shank having a head 4 at one end op osed to the'head 2. b0 y 1 is here shown as slidabl keyed by keys 5 in a sleeve 6 b means 0 which the body is mounted in a c uckor similar device.

A spring 7 located within the upper part of thesleeve encircles an extension'8 of the body and resses upwardly on a head 9 on "the extension and downwardly on an internal annular shoulder 10 onthe sleeve. Theextension 8 is here shown as a screw threading into the upper end of the body.

3 which enter 1 designates the body which is 1n the form' The shank of the The spring permits yielding of the tool holder as it is fed toward the work.

The shank of the tool holding member 3 is hollow or tubular and is externally threaded to receive an internally threaded die. holder '11 in which is held a die for cutting threads. The member 3 may however, hold any other tool.

The upper part of theshan'k of the tool holding member ,3 above the threaded portion on which the die holder 11 is mounted,

is cut away as at 12 to permit chips, etc., to work out.

The head 2 of the body and thehead 4 of the tool holding member are in this form of our invention shown as formed respectively wlth interfitting radial, tongues 13 and grooves 14 on their opposing faces, which, when coupling means to be described, is not tightened up, permit the tool holding memher to shift radially and center itself. After it centers, the coupling means may be tigi ltened.

. he coupling means includes collars 15, 16 associated respectively with the heads 2 and 4, one collar threading into the other.

The collar 15 associated with .the head 2 is formed with an internal annular flange flange 19 bearing .against the rear face of the head 2, is peripherally threaded, and turns in the collar 15.

One of these collars is provided with means for interlocking with the part on which the other collar is located, in order to rotate with said part, and, as here shown, the collar 16 is interlocked withthe head 2 by peripheral shoulders 20 on the head 2 internalnotches 21 in the collar 16. i

Sometimes the center of the work being operated on is out of alinement with the axis of rotation of the body 1 and hence it is necessary to permit the tool holding member to have a centering or radial movement during the entire operation.

prevent the collars 15, 16, from tightening durin the operation, one or more stops are provi ed for holding the collar 16 from" threading into thecollar 15 to its full ex of the collar 15 and having their lnner ends opposed to the upper edge of the collar 16.

Therefore to In operation, the collar 15 can beloosened to permit the tool holding member 3 to shift radially while-rotating andto center itself,

and if the center of the work is true with the axis ofrthe body 1, the collar 15 is tightened to its full amount.- If the center of the work is not true with the center of the body the stop screws 22 areturned inwardly to prevent unintentional tightening of the collars 15, 16 so that the tool holding member 3 may at all times adjust itself to the center of the work.

What we claim is:

1. Aself-centering tool holder comprising a body, and a tool holding member arranged end to end, the body and said member being formed with interlocking means to transmit the rotary movement of the body to said member and permit relative centering radial movement of the body and said member and coupling means between the body and said member comprising complementally threaded collars associated respectively with the body and the said member, one of said collars having means for interlocking with the part on which the other collar is mounted to rotate with said part, substantially scribed.

2. A self-centering tool holder comprisinga body, and a tool holding member arranged end to end, the body and said member being formed with complemental radial" tongues'and grooves on their opposing faces,

to transmit therotary movement of the body to said member and permit relative centering radial movement of the body and said member, and coupling means between the body and said member comprising complementally threaded collars associated respectivel with the body and said member, one of the collars having means interlocking with the part on which the other collar is mounted, to rotate with said part, substantially as and for the purpose specified. A

3. A self-centering too'l holder comprising a body, and a tool holding member arranged end to end, the body and said memr being formed with interlocking means to transmit the rotary movement of the body to said member and permit relative as and for the purpose de-' 'able stop for limiting centering radial movement of the body and said member and coupling means between the body and said member comprising c0mplementally threaded collars associated respectively with the body and the said member, and one o-of the collars having an adjustable stop \for limiting the threading movement of one collar into the other, substantially as and for the purpose set forth.

4. A self-centering tool holder comprising a body, and a tool holding member ar ranged end to end, the body and said member being formed with complemental radial as and for the purpose described.

5. A self-centering tool holder comprising a body,

of the body and said and the collar associated with the tool bolting member having respectively interlocking tongues and notches, substantially and a tool holding member a i-- ranged end to end, the body and said memher being formed with complemental radial tongues and grooves on their opposing faces.

to transmit the rotary movement of the body to said member and permit relative centering radial movement of the body, and said member, and coupling means between the body and said member comprising complementally threaded collars associated respectively with the body, and said member, the

body and the collar associated with the tool I holding member having respectivelyinterlocking tongues and notches, and the collar.

associated with the body having an adjust- 1 the threading movement of the .other collar thereinto, substantially as'and for the purpose specified.

In testimonywhereof we have hereunto signed our names at Syracuse, of Onondaga, and State of New York,.this 28th dayof April, 1919.

WALTER W. BAKER.

in the county FREDERICK w. FRANKLIN. l 

